My girlfriend wants to have sex

Hey, just be honest with her and tell her that you're not comfortable with having sex just yet. Guys shouldn't pressure girls into doing things that they don't want to do but it also goes both ways, girls shouldn't pressure guys into do things that they're not comfortable with also. And if she doesn't respect your feelings about the situation then apparently she isn't the girl for you and hopefully you will find some one that feels the same way you do.

well but what if she gets dissappointed by me?

If she really like/love you like you do her then she will respect your wishes just like you would do the same for her. Don't go against how you feel and what you believe just because she wants to have sex. Trust me if the way you feel is serious then if you do do this because of her then you will regret it and feel guilty about it. And in my opinion if you tell her how you feel and she still insists on it then she's only with you for that and she will eventually find a guy that will do it (which wouldn't be good on her part). It's worth the wait.

yeah what jay12 said and at 13 you really should not have sex yet and since you can't buy condoms you would most likely get your girlfriend pregnant

No condoms for protection, no sex intercourse. Unless you are ready to become a parent before finishing high school. If she is really turned on and you are too, suggest oral. You can both learn each way expirimenting on techniques. Mutual masturbation is also a good learning method which won't get her pregnant.

Buying condoms is not an issue, you can buy them at your age. But it all comes back to your feelings about it, and whether or not you're ready to take on the responsibilities not just physically but also emotionally. I think that guys go through an emotional change just like us girls do. Just think it all over, weigh out all your outcomes and whether or not you're ready to take on all the things that comes with having sex. In the end it's you decision and your's only. It's no one's place to judge you, because the reality is is that kids are having sex younger and younger each generation, so no matter what any one tells you or tries to force on you by telling you "Oh, it's wrong" or "Oh, you're so young" .... if you really want to then no matter what you're going to find a way to get it. So it's you and your decisions and whether you can deal with those decisions or not.